This week, Microsoft is handing out Vista build 5219 at its Professional Developers Conference in Los Angeles. PC Magazine was able to get their hands on it, trying out a number of new features and observing some slick-looking interface enhancements, such as true 3D windows views (with properly skewed video), thumbnail views for desktop apps, and a semi-transparent Taskbar. Take the guided tour to witness some of these new features in build 5219.